Subject(s)
COVID-19 , Mediterranean Region , Communicable Diseases , Laboratories , Disease Outbreaks , BetacoronavirusABSTRACT
First Few X cases (FFX) investigations and Household transmission investigations (HHTI) are essential epidemiological tools for early characterisation of novel infectious pathogens and their variants. We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies HHTI protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines (PROSPERO registration: CRD42021260065). We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for Unity-aligned FFX and HHTI published between 1 December 2019 and 26 July 2021. Standardised early results were shared by WHO Unity Studies Collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by WHO Unity Studies collaborators) were retained in the systematic review and 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2%-90% (95% prediction interval: 3%-71%; I2 = 99.7%); I2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. The large, unexplained variance in hSAR estimates emphasises the need for improved standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses.
ABSTRACT
COVID-19 affected different countries differently. The WHO/ PNIPH, WHO/EMRO, and the Palestinian MoH, with assistance from the PCBS carried out a serological survey in the occupied Palestinian Territories in order to estimate the actual number of COVID-19 infection by the end of December 2020. A sample stratified by Region, district, and by type (urban, rural, and refugee camp), and accounting for gender, was taken from Gaza and the West Bank. The results show that 39% of the oPt (38% of the West Bank and 40% of Gaza), had been infected with COVID-19 by the end of December, almost 10 times the number that was detected by targeted Rt-PCR testing.
Subject(s)
COVID-19ABSTRACT
Background: In Yemen; initial surveillance of COVID-19 focused primarily on patients with symptoms or severe disease, and, as such, the full spectrum of the disease, are not clear that make the epidemiology of COVID-19 is uncertain. To the best of our knowledge, this is the first seroprevalence study done in Yemen to measure the seroprevalence of anti-SARS-CoV-2 antibodies in the general population by sex and age group in Aden, Yemen.Methods: It is a one-time cross-sectional investigation among 2000 participants from all age groups from four districts in Aden at southern Yemen. A multi-stage sampling method used. Data collected by using a well-structured questionnaire and blood sample were collected. Healgen COVID-19 IgG/IgM Rapid Test Cassette was used in all participants. All positive RDT and 14% of the negative RDTs underwent ELISA test (WANTAI SARS-CoV-2 Ab Elisa Kit). Results: A 549 out of 2001 participants were RDT positive and proved by ELISA giving the prevalence of COVID-19 infection to 27·4% and specifically the prevalence of IgG was 25%. The prevalence of asymptomatic COVID-19 infection in all the study group was 7·9%. The highest prevalence was observed in Al-Mansurah district (33·4%). Regarding socio-demographic factors females, housewives and history of contact with COVID-19 patients have significant higher prevalence rates (32%, 31% and 39% respectively).Interpretation: high prevalence of SARS-CoV-2 antibodies was reported. Household contacts are the main factors for transmission. Enhancing population immunity is recommended by introducing COVID-19 vaccine.Funding: The study was funded from WHO/ EMRO. Aden OfficeDeclaration of Interest: None to declare. Ethical Approval: This study was approved by the University of Yemen.